Jump to content

Auto transmisions


phil munga

Recommended Posts

Hi all, I've been having a bit of bother with two of my vehicles both auto ,, one a Mercedes W140 the trans was slipping so set to this weekend removing the box ,

 

now having never looked inside an auto trans before and going by the amount they cost to overhaul I thought I'd have a go at stripping it down :shocked:

 

Laid all parts in order was just like a few motorcycle clutches some gears like a reduction hub doubled up ( believe this'll be reverse ) a couple of brake bands Governor and valve block no special tools required to do this job ,,

I got hold of another box that first gear was broke (new first was OK on mine) so striped it down inspected all parts ferodo material worn on first ,other clutch packs OK ,

the box I removed from my car 2nd and 3rd burnt out this was due to an oil leak :( ,, anyhow got it all back together and there was no chance of lifting the box back in while laid under the car, front on axle ramps rear on stands , so welded some 50mm flat bar to the trolley jack to hold the box and jack it up into place :) , fill with oil and tested it while rear in the air , it all worked very nicely so went for a drive all working as it should :) really chuffed but think one of the coil-packs maybe playing up now as when under load it misfires a bit ,

 

my Jeep auto is also playing up not changing into 3rd so have to work out whats wrong with this one :( all the fun of motoring

Link to comment
Share on other sites

You obviously ignored the bit in the Haynes manual were it says "repairs to this unit are beyond the scope of the home mechanic, please refer the unit to a dealer or specialist". They omit to mention the huge pain incurred as your wallet is bashed.

 

Glad to see someone isn't put off. Think I'd be having a look inside an autobox myself before getting someone else to charge me for the pleasure. I've done a few manual boxes without problems.

 

Looking in a few of the American 4x4 mags a couple of years back there seemed to be plenty of articles on stripping your auto tranny down and modifying it. Seemed the normal thing over there were they've been more used to living with auto's for a lot longer. Guess it helps that any special tools and parts are also cheaper over there.

 

Suspect that the more modern ones with electronic controls and solenoids valves may be a different matter.

Link to comment
Share on other sites

You obviously ignored the bit in the Haynes manual were it says "repairs to this unit are beyond the scope of the home mechanic, please refer the unit to a dealer or specialist". They omit to mention the huge pain incurred as your wallet is bashed.Glad to see someone isn't put off.

Stormin, just thought I'd have a look inside it , This box is very much the same as fitted to the later Haglunds I've been told , I have a VW works manual for a VW T25 auto trans that shows parts inside but will be a long time since I looked through it ,

 

 

 

Looking in a few of the American 4x4 mags a couple of years back there seemed to be plenty of articles on stripping your auto tranny down and modifying it. Seemed the normal thing over there were they've been more used to living with auto's for a lot longer. Guess it helps that any special tools and parts are also cheaper over there.

 

Suspect that the more modern ones with electronic controls and solenoids valves may be a different matter.

yes I was lucky with my box it was just before the change ,, but my jeep box has electronic controls , think If I'm lucky it might just be a speed sensor

Link to comment
Share on other sites

Suspect that the more modern ones with electronic controls and solenoids valves may be a different matter.

 

 

Back in 1991, I was on a DROPS repair course, it was three weeks long....one week was taken up with the ZF auto transmission. No chance in stripping one in your own garage though, because the gear train cannot be removed from the alloy casing without the casing being heated. A test console is used to test the box so without this you could be wasting a lot of tiem and money finding a fault.

Link to comment
Share on other sites

Hi, Richard some of the parts in my Mercedes box can be interchanged with some of the ZF parts because I found out today you can get some heavier ZF parts to go in the trans for the Hagglunds ,,the boxes you worked on in 91 were they electronic ? I new the fault on my gearbox because it had an unnoticed leak so 2nd and 3rd burnt ,,,,,, The Jeep is 2001 and took it to the main dealers on a trailer and they came up with no faults :mad: at a cost of about 200 pounds , I looked up on the internet and found common fault speed sensor , also found that the brake bands can be torque adjusted so did this and the box worked for half a mile , so not sure if it might just be a brake band ,, heres a few pics of the merc box

 

silverbusplusyouthsdadsbuspics302.jpg

 

silverbusplusyouthsdadsbuspics278.jpg

 

Double planetary type gears for reverse

 

silverbusplusyouthsdadsbuspics274.jpg

Link to comment
Share on other sites

Hi, Richard some of the parts in my Mercedes box can be interchanged with some of the ZF parts because I found out today you can get some heavier ZF parts to go in the trans for the Hagglunds ,,the boxes you worked on in 91 were they electronic ?

 

 

 

Hi Phil,

They were electronic, but a lot bigger than those you are working one, they were used in the Leyland DROPS.

Link to comment
Share on other sites

I will have to do this when I lay my hands on a box as basically I am not handing over cash for what I would expect to be shoddy work.

 

Plus like you mentioned there are several upgrades that can be fitted.

 

I think it will help that I have the ZF overhaul manual for the Pinz

 

What did it cost for spare parts? Did you get new bearings to?

Link to comment
Share on other sites

Hi, out of both trans I managed to get enough good parts ie the clutch plates still had writing on the waring surface bearings where all OK , I did have another source for new parts and the clutch type plates are only about 7 pounds each , for the gear that my car sets off in ( said to be 2nd ) has 7 plates then the other two about 6 , there was only one seal ( nylon? ) needed where the main pump fits the input shaft , I'll try and find out a bit more about the upgraded parts for the ZF , from what I remember there from a Mercedes Sprinter

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...